About osseointegration

Bone anchored prostheses for above knee amputated patients

Hundreds of thousands of people all over the world have had a leg amputated due to accidents, diseases or landmines. In 2005 Sahlgrenska University Hospital will be seeing 40-50 above knee amputated patients from outside of Sweden, in order to attach leg prostheses using titanium screws, a process known as osseointegration. The method, in which Sweden is a world leader, enables above knee amputated patients to live virtually normal lives. Patients with other types of amputation also receive osseointegration treatment.

What is osseointegration?

Osseointegration (os = bone) is a method of attaching prostheses directly into the bone, and was developed in the 1960s by Professor Per-Ingvar Brånemark. Brånemark discovered that titanium was not rejected by the body, but instead integrated with the surrounding osseous tissue. The process was initially used to treat toothlessness through dental titanium implants – a treatment that has spread worldwide and improved quality of life for millions of people. Since then the method has been developed, and today osseointegration is also used for leg, arm and face prostheses, and for attachment of hearing aids.

In 1990 the first osseointegrated implant was performed on a patient with an above knee amputation. Since then just over 75 patients have been treated, most with excellent results, and the method is now scientifically recognised internationally.

Why bone anchored leg prostheses?

The majority of patients with an above knee amputation are offered a prosthesis suspended on the residual limb by a conventional socket. Common problems associated with such sockets are pain, chafing, poor attachment and consequently poor mobility. Some above knee amputated patients are unable to use prosthetic sockets at all for one reason or another. Moreover, the socket is a costly affair in the long term, as it has to be regularly replaced and adjusted. These complications also affect the quality of life of the people who use the prostheses.

Bone anchored prostheses eliminate many of the problems that arise with a prosthetic socket. Patients do not experience problems with sweating, chafing or pain, the prosthesis is easy to attach and remove (don and doff), and attachment is stable which allows the user greater mobility. While a prosthesis can never fully replace an arm or a leg, studies of patients treated with osseointegration show a significant increase in quality of life.

How is the procedure carried out?

The surgical procedure is performed in two stages. In the first operation, a specially designed titanium screw known as a fixture, is inserted into the marrow space of the residual limb. The fixture and the surrounding osseous tissue are then left to heal and integrate for six months with no load. During this period, some patients can use a socket prosthesis. The first surgical procedure requires the patient to be hospitalised for 5-7 days.

In the second operation, a titanium extension known as an abutment is attached to the bottom of the fixture, and brought out through a hole in the skin. The actual prosthesis is then attached to this abutment. The second surgical procedure requires the patient to stay in hospital 10-12 days. The skin is given special dressings over two to three weeks after the surgery.

Surgery is followed by rehabilitation and provision of a prosthesis, which are carried out under the supervision of a physiotherapist and an prosthetist at the Sahlgrenska University Hospital Department of Prosthetics and Orthotics. Training the bone to cope with loading begins 4-6 weeks after the second operation. Full load and walk without support are permitted after about 6 months. The overall length of the treatment including both operations, rehabilitation and prosthesis provision is estimated at around 12 months.

During the rehab period, the patient makes regular visits to the Rehabilitation Centre for persons with a lower limb amputation at the Department of Prosthetics and Orthotics, Sahlgrenska University Hospital. However, day-to-day training takes place more locally for the patient.

What complications can arise?

As with all surgical treatment, there is a risk of complications which can alter the treatment or compromise the results. For instance, superficial infections can arise around the abutment, as well as infections in the bone itself. The fixture or abutment may work loose or the attachment or bone may fracture, but most complications can be remedied.

Who can get this treatment?

An individual assessment is carried out from case to case to determine whether the procedure is appropriate or even feasible. Patients with severe problems using a socket prosthesis, or even unable to use one for some reason, are particularly well suited for this method. The treatment is not primarily intended for patients who have had to have an amputation due to poor blood circulation.

Moreover, before a decision on treatment is made, each patient is called to a team assessment for further examination and information.

Non-residents of Västra Götaland require a specialist referral to receive highly specialised care at Sahlgrenska University Hospital. Foreign nationals require a payment guarantee to receive treatment at Sahlgrenska University Hospital. All financial and administrative issues for foreign nationals are dealt with by Sahlgrenska International Care.